Much has been made of Benjamin Holt’s contributions to the development of the crawler tractor. And for good reason since Holt pioneered the many advances that made his Caterpillars some of the most popular crawlers of their time.
Often overlooked, however, is the engineering and business genius of C.L. Best and his Tracklayer tractors. Best is often given begrudging acknowledgment, at most, as being a fierce rival of Holt prior to the creation of Caterpillar Tractor Company in 1925. Bear in mind that Caterpillar Tractor was created by a merger of the Best and Holt interests as opposed to Holt buying out Best’s firm.
Best’s impact on the newly created firm was immense. He led the firm as chairman of its board which was a position he held until 1951.
And Best’s advanced engineering, embodied by his Model 60, provided the template by which most postmerger Caterpillar crawlers would be fashioned.
When introduced in 1919, the Best 60 quickly established itself as the standard by which all other crawlers would be measured. A major advance in the evolution of the crawler, the 60 offered numerous engineering firsts including:
- Oscillating track sections that, besides greatly smoothing the crawler’s ride, kept the tracks in solid contact with the ground, providing increased traction in rough surface conditions.
- Extensive use of antifriction bearings, particularly in the track assembly, to reduce friction and wear in crucial mechanical areas.
- A two-speed transmission that was later increased to three gear sets to allow the operator to match crawler speed to the workload.
- A steering system that employed roller-bearing-mounted, multiple-disc enclosed friction clutches.
This approach to steering, in particular, set the Best 60 apart from its competition at the time. The design applied power to both tracks even when the 17,500-pound crawler was being turned. A huge differential enabled the crawler tractor to pull just as hard around a corner as on the straightaway.
Beefy, smooth operating engine
Topping off the 60 – and one of the crawler’s best assets – was a workhorse of an engine designed and built by Best Tractor. This four-cylinder, valve-in-head power plant (6½x8½ bore-and-stroke) turned out 56 hp. when first evaluated at the Nebraska Tractor Test.
That output reached the manufacturer’s rating of 60 hp. at the belt (30 hp. at the drawbar) when the Tracklayer was retested three years later. And testifying to the engine’s ability to pump out reserve power, the Tracklayer delivered a whopping 72½ brake hp. under maximum load evaluation. Again, Best employed antifriction bearings throughout his engines, making the units particularly rugged and long lived.
With all these attributes, the Tracklayer 60 fast gained a reputation as being a premium crawler being sold at a competitive price of $5,750 (in 1922).
Sensibly, the 60 and its little brother, the Tracklayer 30, were readily adopted into the new Caterpillar Tractor line with no changes save for a switch in color and new titles. The Caterpillar Sixty and Thirty would be replaced a short time after the Holt-Best merger. But elements of these tractors’ design would be seen in Caterpillar crawlers for years to come.